Vented draining slack adjuster end cap

ABSTRACT

A vented cap for a main spring housing of a slack adjuster including an inner portion having an inner seal surface configured for cooperating with an elongated rod member and an outer seal surface configured for cooperating with a sidewall located at an end portion of the main spring housing. The vented end cap includes at least one opening configured to allow fluid and/or contaminants trapped within the slack adjuster and/or the end cap to drain therethrough. Various seals and/or drainage openings can also be provided along the slack adjuster to prevent the entrance of and/or allow for drainage of fluid/contaminants from the slack adjuster. A method for preventing the accumulation of fluid and/or contaminants within a slack adjuster and for protecting a critical operating area of the slack adjuster is also provided.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is entitled to and claims priority of U.S.Provisional Patent Application No. 62/112,996, filed on Feb. 6, 2015,entitled “Vented Draining Slack Adjuster End Cap” the disclosure ofwhich is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure is directed to a slack adjuster whichautomatically adjusts the slack in the brake rigging of a railwayvehicle, and further, particularly, to a slack adjuster including a mainspring housing end cap that also functions as an exit location forfluids and other contaminants that may enter the main spring housing ofthe slack adjuster, while preventing fluid and other contaminants fromentering into the slack adjuster.

Description of Related Art

Slack adjuster assemblies have been employed in brake riggings tocompensate for slack caused by wear induced in the brake pads, wheels,and other components in brake rigging during repeated brakingapplications. By controlling this slack, the brake piston travel isautomatically maintained at the correct length to ensure maximumefficiency in the brake system. The slack adjuster is also used toautomatically adjust the slack in the brake rigging for various otherreasons. One reason is to maintain the brake cylinder piston rod traveldistance within a prescribed limit, which is of particular importance inpresent day higher speed operations. In addition, today's railwayvehicles have a greater number of cars due to better locomotiveequipment. For these reasons, it is important that the piston rod travelof the brake cylinder be maintained at a relatively close tolerance inorder to properly balance the fluid pressure, usually air, in the fluidcylinder with that in the reservoir. Another important reason is thatthe slack adjusters will provide a substantially more uniform brakingforce to be applied to each set of wheels on each car making up a train.

One example of a slack adjuster that is used in a wide variety ofrailway applications is a double-acting compression-type slack adjuster,which is described in U.S. Pat. No. 4,662,485 and incorporated herein byreference. This slack adjuster assembly includes an elongated hollowhousing member restrained against rotation and pivotally connectable ata first end thereof to a brake rigging. An elongated rod member, whichis restrained against rotation and pivotally connectable at a first endthereof to the brake rigging, is provided within this housing and has atleast a threaded portion adjacent a second end thereof. The threadedportion of the rod member extends into and is reciprocally movablewithin the housing through a second end of the housing. A positioningmeans, such as a cone lock nut located within a cone nut housingportion, movable between respective first abutting engagement,disengagement, and second abutting engagement positions, is threadablyengaged with the threaded portion of the rod member intermediate theends thereof. The cone lock nut rotates about the threaded portion ofthe rod member when in the disengaged position, thereby changing thelength of the slack adjuster assembly by changing the relativelongitudinal position between the housing and the rod member. A pair ofopposite facing abutment surfaces positioned within a portion of thehousing and a pair of opposed abutting surfaces carried by the cone locknut for engaging respective adjacent surfaces to resist rotation of thecone lock nut about the rod member when the cone lock nut is in one ofthe respective abutting engagement positions thereby retarding thechange in relative longitudinal position between the housing and the rodmember are provided. A first urging means is positioned between the conelock nut and an abutment surface carried by the rod member for urgingthe cone lock nut into the disengaged position. A second urging means ispositioned between the first end of the housing and the cone lock nutfor overcoming a force applied by the first urging means and for urgingthe cone lock nut into the first abutting relationship position. An overtravel control means located within an over travel control housing ispositioned to reciprocally move in a longitudinal direction adjacent thefirst end of the housing and is engageable with the second urging meansfor reducing the force applied by the second urging means to less thanthe force applied by the first urging means, thereby allowing the conelock nut to move to the disengaged position. An over travel controlactuating means is positioned to engage the over travel control meansfor actuating the over travel control means in response to the traveldistance of a brake cylinder piston connected to the brake rigging.

Other examples of slack adjusters include the Universal Model 2300-DJ,owned by the Assignee of the present disclosure, Ellcon National ModelD-2000, and New York Air Brake Model KDR-482-E.

During use of the brake rigging, the slack adjuster is exposed tovarious environmental conditions, including conditions where the slackadjuster is exposed to large amounts of fluid, such as water. This waterand other contaminants from the environment can accumulate and becometrapped within the slack adjuster in the main spring housing or even inthe critical operating area and near critical components of the slackadjuster, which can compromise the functioning of the slack adjuster. Inone example, such as in the Universal Model 2300-DJ, the criticaloperating area includes the cone nut, bearing race assembly, and theconical spring, all of which operate together to allow the slackadjuster to adjust the brake rigging of the railcars as needed. It canbe appreciated that different slack adjuster designs may includeadditional and/or other components within the critical operating area.

Some slack adjuster designs include a seal, such as a wiper seal,installed at the end cap of the main spring housing wherein the slackadjuster rod moves in and out. This seal is provided with the intendedpurpose of preventing fluid, such as water, and contaminants fromentering into the slack adjuster. However, when a slack adjuster isexposed to large amounts of water, this wiper seal can fail to block allof the water from entering into the main spring housing, affectingspring performance and washing out operating grease and, subsequently,entering into the critical operating area of the slack adjuster. Thus,in these instances, water and contaminants may enter into the mainspring housing and then into the critical operating area, deleteriouslyeffecting the components located therein, resulting in faulty operationof the slack adjuster. Accordingly, there is a need in the art toprovide an exit location for the water and contaminants that breach thiswiper seal and enter into the main spring housing. There is also a needin the art to reduce and/or prevent the entrance of water andcontaminants from entering into the main spring housing. Providing thisexit location and preventing/reducing the amount of fluid and/orcontaminants that enter into the main spring housing will maintainoptimal operation of the spring in the main spring housing and thecritical operating components of the slack adjuster by preventingaccumulation of water and contaminants near the critical areas of theslack adjuster. The system for preventing this accumulation of water andprotecting the critical operating area from contaminants must beadaptable to all slack adjusters and orientations of installation, suchthat the slack adjuster can be used in a wide array of environmentalconditions.

SUMMARY OF THE INVENTION

In accordance with an aspect of the present disclosure, a vented end capfor a main spring housing of a slack adjuster is provided. The end capincludes an inner portion having an inner seal surface configured forcooperating with an elongated rod member of the slack adjuster and anouter seal surface configured for cooperating with a sidewall located atan end portion of the main spring housing. The end cap includes at leastone opening configured to allow fluid and/or contaminants to draintherethrough.

According to one embodiment, the at least one opening can comprise aradially extending aperture in fluid communication with the innerportion and the outer seal surface. The radially extending aperture ispositioned at a location to allow the fluid and/or contaminants to drainout of the inner portion of the end cap prior to breaching the innerseal. An aperture can be provided through the sidewall located at theend portion of the main spring housing. This aperture in the sidewall isin alignment with the radially extending aperture so as to permit thefluid and/or contaminants to drain out of the end cap and housing. Theend cap can include multiple openings wherein each of the openingscomprises a radially extending aperture associated therewith. The endcap can further comprise one or more longitudinally extending aperturein fluid communication with one or more of the radially extendingapertures and with an interior of the main spring housing. Theselongitudinally extending apertures are capable of draining any fluidand/or contaminants that breach the sealing surfaces and become trappedwithin the main spring housing.

According to another embodiment, the at least one opening can comprise acut-out portion in the outer seal surface.

According to yet another embodiment, the at least one opening cancomprise a channel formed in the outer seal surface wherein the channelis defined by a first lip portion and a second lip portion. According toone design, the first lip portion has a first height and the second lipportion has a second height, and the first height is less than thesecond height. The end cap can be associated with the main springhousing such that the first lip portion faces in an outward directionwith respect to the interior of the main spring housing, and the secondlip portion faces the interior of the main spring housing. The at leastone opening can further include one or more cut-out portions in theouter seal surface wherein the cut-out portions extend through the firstand second lip portion in a direction that is perpendicular with respectto the channel.

The inner portion of the end cap can comprise an inner channel definedby a first ledge portion and a second ledge portion. The first ledgeportion defines a first diameter and the second ledge portion defines asecond diameter, and the inner seal is designed such that the firstdiameter is greater than the second diameter. The inner channel candefine a third diameter that is greater than the first and seconddiameters. The inner channel has a size which accommodates a rod seal orwiper seal.

The end cap outer seal can be a channel defined by the first lip portionand the second lip portion that are integrally formed with the end cap.The second lip portion can include an angled surface extending in anoutward direction with respect to the channel.

The opening in the end cap is configured to drain fluid and contaminantsthat become trapped in the end cap or the main spring housing.

In accordance with another aspect of the present disclosure a drainagesystem for use with a slack adjuster for a railway brake rigging systemis provided. The slack adjuster includes at least a main spring housingand a cone nut housing enclosing a critical operating area of the slackadjuster. The critical operating area includes components configured tooperate together to adjust the brake rigging. The drainage systemincludes an end cap having an inner portion having an inner seal surfaceconfigured for cooperating with an elongated rod member and an outerseal surface configured for cooperating with a sidewall located at anend portion of the main spring housing. The end cap includes at leastone opening configured to allow fluid and/or contaminants to draintherethrough and out of the slack adjuster to reduce exposure ofcomponents within the main spring housing and exposure of the criticaloperating area of the slack adjuster to the fluid and/or contaminants.Longitudinally extending apertures can be provided in fluidcommunication with the radially extending apertures and an interior ofthe main spring housing to drain fluid and/or contaminants out of themain spring housing.

According to one embodiment, the at least one opening can comprise aradially extending aperture in fluid communication with the innerportion and the outer seal surface, and the system can further includean aperture extending through the sidewall located at the end portion ofthe main spring housing in alignment with the radially extendingaperture through the end cap. This radially extending aperture can bepositioned at a location to allow the fluid and/or contaminants to drainout of the inner portion of the end cap and the housing sidewall priorto breaching the inner seal.

According to another embodiment, the at least one opening can comprise achannel formed in the outer seal surface. The channel can be defined bya first lip portion having a first height and a second lip portionhaving a second height, wherein the first height is less than the secondheight. The end cap can be associated with the main spring housing suchthat the first lip portion faces in an outward direction with respect tothe interior of the main spring housing and the second lip portion facesthe interior of the main spring housing. The at least one opening canfurther include a cut-out portion in the outer seal surface wherein thecut-out portion extends through the first and second lip portions in adirection that is perpendicular with respect to the channel.

The inner portion of the end cap can comprise an inner channel definedby a first ledge portion having a first diameter and a second ledgeportion having a second diameter and wherein the first diameter isgreater than the second diameter. The channel can define a thirddiameter that is greater than the first and second diameters.

In accordance with yet another aspect of the present disclosure, amethod is provided for preventing the accumulation of fluid and/orcontaminants within a slack adjuster and for protecting a criticaloperating area of the slack adjuster. The slack adjuster includes a mainhousing having an end cap and a cone nut housing enclosing the criticaloperating area of the slack adjuster. The method comprises providing atleast one opening in the end cap configured to allow fluid to drain outof the end cap and main housing portion to reduce exposure of componentswithin the main spring housing and exposure of the critical operatingarea of the slack adjuster to the fluid and/or contaminants.

The end cap can comprise an inner portion having an inner seal surfaceconfigured for cooperating with an elongated rod member and an outerseal surface configured for cooperating with a sidewall located at anend portion of the main spring housing. The at least one opening cancomprise at least one of a radially extending aperture in fluidcommunication with the inner portion and the outer seal surface, atleast one cut-out portion in the outer seal surface, and a channel inthe outer seal surface defined by a first lip portion and a second lipportion.

In accordance with another aspect of the present disclosure, adouble-acting tension actuatable slack adjuster to adjust the slack in arailway vehicle brake linkage is provided. The slack adjuster comprisesan elongated hollow cylindrical housing member which is restrainedagainst rotation and pivotally connectable at a first end thereof. Theelongated hollow cylindrical housing includes a main spring housinghaving an end cap at an end of thereof, a cone nut housing, and an overtravel housing. An elongated rod member extends through the end cap. Therod member is restrained against rotation and pivotally connectable at afirst end thereof. The rod member has at least a portion thereofthreaded, and the threaded portion extends into the housing memberthrough a second end of the housing member. A cone lock nut isthreadedly engaged with the threaded portion of the rod memberintermediate a first and second end thereof. The cone lock nut isaxially movable for rotating about the threaded portion of the rodmember to change the length of the slack adjuster by changing therelative longitudinal position between the housing member and the rodmember. The cone lock nut is located within the cone nut housing. Atleast a first spring is provided for urging the cone lock nut into afirst position with respect to the housing member. A second spring isprovided for overcoming a force applied by the first spring and forurging the cone lock nut into a second position. The slack adjuster alsocomprises at least one drainage system for allowing fluid and/orcontaminants to drain out of the slack adjuster wherein the at least onedrainage system is associated with the end cap of the main housing.

The end cap can comprise an inner portion having an inner seal surfaceconfigured for cooperating with the elongated rod member and an outerseal surface configured for cooperating with a sidewall located at anend portion of the main spring housing. The at least one opening cancomprise at least one of a radially extending aperture in fluidcommunication with the inner portion and the outer seal surface, atleast one cut-out portion in the outer seal surface, and/or a channel inthe outer seal surface defined by a first lip portion and a second lipportion. The slack adjuster can also include various seals and/ordrainage locations along the body of the slack adjuster. According toone embodiment, at least one opening can be provided in the over travelhousing portion. According to another embodiment, at least one openingcan be provided in the main spring housing. These openings areconfigured to allow fluid and/or contaminants to drain there through,thus reducing exposure of the critical operating area of the slackadjuster to the fluid and/or contaminants. At least one of a plug,one-way valve, and/or a patch can be provided to cover or seal the atleast one opening in the over travel housing portion and/or the mainspring housing. According to one embodiment, a single patch can beprovided for covering multiple openings in the over travel housingportion and/or the main spring housing, leaving a single or a few of theopenings uncovered. In this embodiment, the user can then install theslack adjuster such that the uncovered opening or openings are facing ina downward direction to allow fluid or contaminants to drain therethrough and out of the slack adjuster.

According to yet another embodiment and/or in addition to the openingsdescribed above, the slack adjuster can include one or more seals orsealing systems configured for cooperating with at least one of the mainhousing portion, cone nut housing portion, and over travel housingportion to seal the critical operating area against entrance of fluidand/or contaminants therein or to reduce exposure of the criticaloperating area to fluid and/or contaminants. It can be appreciated thatany of the sealing systems or drainage systems described above can beused alone or cumulatively in any combination along with the vented endcap to achieve the necessary sealing and/or drainage of the slackadjuster assembly so as to protect the critical operating area fromfluid and/or contaminants.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a double acting automatic slack adjusterfor use with a railway brake rigging including a vented end cap fordrainage in accordance with an embodiment of the present disclosure;

FIG. 1A is a partial cross-sectional view of the slack adjuster of FIG.1, showing a critical operating area of the slack adjuster in accordancewith an embodiment of the present disclosure;

FIG. 2 is an expanded perspective view of the slack adjuster of FIG. 1,including the vented end cap in accordance with an embodiment of thepresent disclosure;

FIG. 3 is a side elevation view of the double acting automatic slackadjuster of FIG. 1, including a partial cross-sectional view showing thevented end cap in accordance with an embodiment of the presentdisclosure;

FIG. 3A is a detail view “A” of the vented end cap of FIG. 3 inaccordance with an embodiment of the present disclosure;

FIG. 3B is a cross-sectional view of the vented end cap taken along lineB-B of FIG. 3A in accordance with an embodiment of the presentdisclosure;

FIG. 4A is a perspective view of a main spring housing including thevented end cap in accordance with an embodiment of the presentdisclosure;

FIG. 4B is an enlarged cross-sectional view of the main spring housingand vented end cap of FIG. 4A in accordance with an embodiment of thepresent disclosure;

FIG. 5A is a perspective view of a vented end cap of FIGS. 4A and 4B inaccordance with an embodiment of the present disclosure;

FIG. 5B is an enlarged cross-sectional view of the vented end cap ofFIG. 5A in accordance with an embodiment of the present disclosure;

FIG. 5C is an end view of the vented end cap of FIG. 5A in accordancewith an embodiment of the present disclosure;

FIG. 5D is a detailed view “D” of a portion of the vented end cap ofFIG. 5B;

FIG. 6A is a perspective view of a main spring housing including thevented end cap in accordance with another embodiment of the presentdisclosure;

FIG. 6B is an enlarged cross-sectional view of the main spring housingand vented end cap of FIG. 6A in accordance with an embodiment of thepresent disclosure;

FIG. 6C is an end view of the main spring housing and vented end cap ofFIG. 6A in accordance with an embodiment of the present disclosure;

FIG. 7A is a perspective view of the vented end cap of FIGS. 6A-6C inaccordance with an embodiment of the present disclosure;

FIG. 7B is an enlarged cross-sectional view of the vented end cap ofFIG. 7A in accordance with an embodiment of the present disclosure;

FIG. 7C is an end view of the vented end cap of FIG. 7A in accordancewith an embodiment of the present disclosure;

FIG. 8 is an expanded perspective view of a double acting automaticslack adjuster for use with a railway brake rigging including a ventedend cap and a drainage system in accordance with an embodiment of thepresent disclosure;

FIG. 9 is a perspective view of a double acting automatic slack adjusterfor use with a railway brake rigging including a vented end cap and adrainage system in accordance with an embodiment of the presentdisclosure;

FIG. 10 is an expanded perspective view of the slack adjuster of FIG. 9in accordance with an embodiment of the present disclosure; and

FIG. 11 is a top view of the patch used for covering the apertures inthe main spring housing and/or the over travel housing in FIGS. 9 and 10in accordance with an embodiment of the present disclosure.

DESCRIPTION OF THE INVENTION

For purposes of the description hereinafter, the terms “upper”, “lower”,“right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “lateral”,“longitudinal”, and derivatives thereof, shall relate to the disclosureas it is oriented in the drawing figures. However, it is to beunderstood that the disclosure may assume various alternativevariations, except where expressly specified to the contrary. It is alsoto be understood that the specific devices illustrated in the attacheddrawings, and described in the following specification, are simplyexemplary embodiments of the disclosure. Hence, specific dimensions andother physical characteristics related to the embodiments disclosedherein are not to be considered as limiting.

Reference is now made to FIGS. 1-3 which show a double acting slackadjuster, generally indicated as 10, for use in a railway vehicle brakelinkage, not shown, to automatically adjust the slack within the brakelinkage caused by wear induced in the brake pads, wheels, and othercomponents in the brake rigging during repeated braking applications.The slack adjuster includes a vented end cap 100, configured to functionas an exit location for fluids and other contaminants that may enter themain spring housing 20 of the slack adjuster 10 and to reduce oreliminate fluid and other contaminants from entering into the slackadjuster 10 which ultimately reduces exposure of the critical operatingarea, generally indicated as 70 in FIG. 1A, to fluid and/orcontaminants. The slack adjuster critical operating area 70 is definedin detail below, but generally refers to the area including thecomponents which operate together to adjust the brake rigging of therailcars as needed.

With continuing reference to FIGS. 1-3, the slack adjuster 10 includesan elongated hollow cylindrical housing member 12 which is restrainedagainst rotation. The slack adjuster 10 is pivotally connectable at afirst end, generally indicated as 15 thereof, to the brake rigging witha front jaw 16 and pivotally connectable at a second end, generallyindicated as 17 thereof, to the brake rigging with a rear jaw 18. Thesecond end 17 of the housing member 12 includes the vented end cap 100,in accordance with the present disclosure, and a wiper seal 102. Thefirst end 15 of the slack adjuster 10 also includes a control rod 19.The elongated cylindrical housing member 12 includes the main springhousing 20, a cone nut housing portion 22, and an over travel housingportion 24. With particular reference to FIG. 2, the slack adjuster 10also includes a rod assembly 25 including an elongated rod member 26positioned for reciprocal movement within the housing member 12 throughthe second end 17 of the housing member 12, which is also one end or therear end of the main spring housing 20. The rod member 26 is restrainedagainst rotation and pivotally connectable at a first end 28 thereof tothe railway brake rigging by the rear jaw 18. The rod member 26 has athreaded portion 30 adjacent a second end 32 that extends into thehousing member 12 and through the first end 15 of the housing member 12.The main spring housing 20 and/or the elongated cylindrical housingmember 12 can also include a decal or identification label 47, as shownin FIG. 2.

With continuing reference to FIGS. 1-3, and with reference to FIG. 1A,the slack adjuster 10 includes the critical operating area 70. Thiscritical operating area 70 includes the components of the slack adjuster10 which operate together to adjust the brake rigging. One example of acritical operating area is shown in FIG. 1A and includes a positioningmember, such as a cone lock nut 72 that is located within the cone nuthousing portion 22, and threadedly engaged with the threaded portion 30of the elongated rod member 26. The cone lock nut 72 rotates about thethreaded portion 30 of the elongated rod member 26 between respectivefirst abutting engagement, disengagement, and second abutting engagementpositions to change the length of the slack adjuster 10 by changing therelative longitudinal positions between the housing member 12 and theelongated rod member 26.

The slack adjuster 10 also includes a first urging assembly which caninclude at least one main or first spring 34, an additional spring 36located within a spring cup 38, and a conical spring 74, located withinthe critical operating area 70 for urging the cone lock nut 72 into afirst position, such as a disengaged position, with respect to thehousing member 12. The conical spring 74 can be caged between the conelock nut 72 and a conical spring seat 76. It can be appreciated that thesprings 34, 36 can be replaced with other types of urging members, suchas pneumatic or hydraulic cylinders.

A second urging assembly is also provided which, according to oneembodiment, can include a second spring or over travel spring 40 locatedwithin an over travel spring housing 41. The over travel spring 40 isstronger than the first or main spring 34 so as to overcome the forceapplied by the first or main spring 34 and, therefore, urge the conelock nut 72 into a second position. It can also be appreciated that,like the first urging assembly, a fluid operated cylinder may be used inplace of the over travel spring 40.

The over travel housing portion 24 can also include a rod guide 42threaded at a first end 42 a and a second end 42 b and configured forcooperating with the elongated rod member 26 and over travel spring 40.An over travel sleeve 44 can be provided between at least a portion ofthe rod guide 42 and the over travel spring 40. One or more washers 46can be provided within the over travel housing portion 24.

Other components located at the front end of the slack adjuster 10include an over travel sliding collar 48, an over travel control ringswaging 50, and a machined tube 52. A wiper seal 54 and a retaining ring56 may also be provided at this front end. A wiper seal 90 may also beprovided in the over travel housing assembly 24. As discussed above, thewiper seal 102 is provided at the rear end or the back entrance near thevented end cap 100 of the main spring housing 20. Prior to the presentdisclosure, previous slack adjuster designs relied upon these wiperseals to prevent water and contaminants from entering into the slackadjuster 10 and into the critical operating area 70. However, insituations where the slack adjuster is exposed to a large amount ofwater, these wiper seals may be insufficient to prevent the entrance ofwater and/or contaminants from entering into the critical operating area70 of the slack adjuster 10 and causing operational problems with thecomponents located therein which operate together to adjust the brakerigging of the railcar. These operational problems could occur if dirtor other foreign objects become trapped between the moving parts of thecomponents or if any accumulated water surrounding the componentsfreezes, which would inhibit and/or otherwise prevent the normalmovement of the components with respect to one another.

Referring, in particular, to FIGS. 1A and 2, in addition to the conelock nut 72, conical spring 74, and conical spring seat 76, the criticaloperating area 70 includes bearing assemblies, generally indicated as78, including a bearing 80 cooperating with races 82, which are locatedon both sides of the cone lock nut 72. Also included in the criticaloperating area 70 are one or more trigger pins 84 located withinapertures 86 extending into the first end 42 a of the rod guide 42. Oneor more O-rings 92 may be associated with the trigger pins 84 to assistin preventing fluid and/or contaminants from entering into the cone nuthousing portion 22 through the aperture 86 in the rod guide 42. Thecritical operating area 70 can also include a retaining ring 88, theover travel housing portion seal or wiper seal 90, and a front cone 91.

In operation, the cone lock nut 72, the bearing assemblies 78, and theconical spring 74 cooperate together to change a length of the slackadjuster 10 by changing a relative longitudinal position between themain spring housing 20 and the elongated rod 26 located within the mainspring housing 20. The cone nut housing portion 22 is positioned betweenthe over travel housing portion 24 and the main spring housing 20. Asshown in FIG. 1A, the cone nut housing portion 22 includes a first end22 a positioned adjacent to the over travel housing portion 24 and asecond end 22 b positioned adjacent to the main spring housing 20. Asshown in FIG. 2, the cone nut housing portion 22 can include a retainingring 58, a collet 60, and a washer 62. The first end 22 a and the secondend 22 b can also include threads that are configured to cooperate withthreads on the main spring housing 20 and the over travel housingportion 24.

Referring now to FIGS. 3A-3B, 4A-4C, and 5A-5D, the present disclosureis directed to vented end cap 100 for the main spring housing 20 of theslack adjuster 10. The end cap 100 includes an inner portion 101 havingan inner seal surface comprising the wiper seal 102, also shown in FIG.2, configured for cooperating with the elongated rod member 26 of theslack adjuster 10 and an outer seal surface 104 configured forcooperating with a sidewall 106 located at an end portion 108 of themain spring housing 20 and/or the end portion 17 of the elongatedcylindrical housing 12 of the slack adjuster 10. The end cap 100includes at least one opening 110 configured to allow fluid and/orcontaminants to drain therethrough.

According to one embodiment, the at least one opening 110 can comprise aradially extending aperture in fluid communication with the innerportion 101 and the outer seal surface 104. The radially extendingaperture 110 is positioned at a location to allow the fluid and/orcontaminants to drain out of the inner portion 101 of the end cap 100prior to breaching the inner wiper seal 102. An aperture 112 can beprovided through the sidewall 106 located at the end portion 108 of themain spring housing 20. This aperture 112 in the sidewall 106 is inalignment with the radially extending aperture 110 so as to permit thefluid and/or contaminants to drain out of the end cap 100 and housing20. The end cap 100 can include multiple openings 110 wherein each ofthe openings 110 comprises a radially extending aperture associatedtherewith. Longitudinally extending apertures 111 can be provided whichcommunicate with the main spring housing 20 and the radially extendingapertures 110 to allow for draining of any fluid and/or contaminantswithin the main spring housing 20 that breach the sealing surfaces.

With continuing reference to FIGS. 5A-5D, the vented end cap 100 furthercomprises a channel 120 formed in an outer seal surface 104. The channel120 is defined by a first lip portion 122 and a second lip portion 124.As shown in FIG. 5D, the first lip portion 122 has a first height H1 andthe second lip portion 124 has a second height H2 and the first heightH1 is less than the second height H2. The end cap 100 can be associatedwith the main spring housing 20 such that the first lip portion 122faces in an outward direction with respect to the interior 21 of themain spring housing 20 and the second lip portion 124 faces the interior21 of the main spring housing 20. The outer seal surface 104 cooperateswith an inner surface of the sidewall 106 of the end portion 108 of thehousing to form a seal therewith to prevent or reduce the amount offluid and/or contaminants that enter into the housing portion 20. Thevented end cap 100 can include both the radially extending apertures 110and the longitudinally extending apertures 111 discussed in detailabove.

As shown in FIG. 5D, the second lip portion 124 can include an angledsurface 130. According to one embodiment, this angled surface 130 canhave an angle ∂ of approximately 10° with respect to a centerline Cextending through the second lip portion 124. This angled surface 130allows for proper forming of the main spring housing 20 around the endcap 100 and ensure the sealing of the surface in this area.

The end cap 100 can be secured to the end portion 108 of the main springhousing 20 by any well-known technique, such as by crimping or byswaging. Essentially the main spring housing 20 is squeezed around theend cap 100 forming it into place in the channel 120 that runs aroundthe exterior of the cap 100.

As shown in FIG. 5B, an inner portion 101 of the end cap 100 cancomprise an inner channel 114 defined by a first ledge portion 115 and asecond ledge portion 116. The first ledge portion 115 defines a firstdiameter D1 and the second ledge portion 116 defines a second diameterD2. The first diameter D1 is greater than the second diameter D2 and aninner seal surface 103, which cooperates with the rod member 26, isdefined by second ledge portion 116 having the second diameter D2. Theinner channel 114 can define a third diameter D3 that is greater thanthe first diameter D1 and the second diameter D2. The inner channel 114is configured to receive the rod seal or wiper seal 102, as discussedabove and shown in FIG. 3A, and first ledge portion 115 is sized to havea diameter and shape configured to hold a retaining ring to keep theseal 102 in place.

The particular shape of the outer seal 104 of the end cap 100 and theshape of the inner portion 101, along with axially extending apertures110 and longitudinally extending apertures 111, are configured to drainfluid and contaminants that become trapped in the end cap 100 or themain spring housing 20 and also is such that it reduces or preventsentrance of fluids and/or contaminants into the main spring housing 20.

Reference is now made to FIGS. 6A-6C and 7A-7C, which show an end cap200 according to another embodiment of the present disclosure. In thisdesign, the end cap 200 includes at least one or more openings 210 inthe form of a cut-out portion in an outer seal surface 204. An outerchannel 220 can be formed in the outer seal surface 204. The outerchannel 220 is defined by a first lip portion 222 and a second lipportion 224. The first lip portion 222 has a first height H1 and thesecond lip portion 224 has a second height H2. The first height H1 isless than the second height H2. The end cap 200 can be associated withthe main spring housing 20 such that the first lip 222 portion faces inan outward direction with respect to the interior 21 of the main springhousing 20 and the second lip portion 224 faces an interior 21 of themain spring housing 20.

The end cap 200 is a one-piece member that is machined to form thedifferent dimensions including the outer seal surface 204 which ismachined to have a shape and finish 205. The outer seal surface 204 andmachined finish 205 is capable of forming a seal with an inner surface207 of the sidewall 206 at an end portion 208 of the main spring housing20. This outer seal 204 is configured to form a friction fit with thesidewall 206 of the main spring housing to secure the cap 200 in themain spring housing 20 and secured thereto by any well-known technique,such a swaging or crimping, as discussed above.

As shown in FIGS. 7A and 7B, the inner portion 201 of the end cap 200can comprise an inner channel 214 defined by a first ledge portion 215and a second ledge portion 216. The first ledge portion 215 defines afirst diameter D1 and the second ledge portion 216 defines a seconddiameter D2. The first diameter D1 is greater than the second diameterD2 and an inner seal surface 203, which cooperates with the rod member26, is defined by second ledge portion 216 having the second diameterD2. The inner channel 214 can define a third diameter D3 that is greaterthan the first diameter D1 and the second diameter D2. A rod seal orwiper seal, such as 102, shown in FIG. 3A, can be press-fitted intoinner channel 214 and retained therein. First ledge portion 215 andfirst diameter D1 are configured to allow for clearance of the seal andto hold a retaining ring to keep the seal in place.

The particular design of the outer seal surface 204 and the innerportion 201 of the end cap 200 assists in the prevention of fluid and/orcontaminants from entering into the main spring housing 20, and theopenings or cutout portions 210 in the outer seal surface provide anexit point for any fluids and/or contaminants that breach the inner sealor inner seal surface 203 or outer seal surface 204, or enter in via anyother location, and become trapped in the main spring housing 20.

With continuing reference to FIGS. 1-3, in addition to the vented endcaps 100 and 200, described above, the slack adjuster 10 can alsoinclude a drainage system, generally indicated as 95, associated withthe over travel housing portion 24 to enable any fluid and/orcontaminants that become trapped in the slack adjuster 10 to exittherefrom. The drainage system 95 includes at least one opening 27extending through a sidewall portion of the over travel housing portion24. According to one embodiment, the opening can be formed by providingtwo separate portions 24 a, 24 b of the over travel housing portion 24and associating these portions 24 a, 24 b with one another via the plughousing 97, as described below such that opening 27 extends therebetween. The opening 27 is configured to form a direct egress for thefluid and/or contaminants to drain therethrough and to reduce exposureof the critical operating area 70 to fluid and/or contaminants.According to another embodiment, the opening 27 can comprise one or moreapertures formed through a sidewall portion of the over travel housingportion 24.

As discussed above, the plug housing 97 can encompass at least a portionof the over travel housing portion 24. The plug housing 97 includes atleast one aperture 98, or a plurality of apertures 98, extending througha sidewall portion in alignment with the opening 27 or aperturesextending through the over travel housing portion 24. The plug housing97 can threadedly engage the over travel housing portion 24. A removableplug 99 can be provided to close the aligned openings or apertures. Theplug 99 can be in the form of a one-way valve, a patch, or a sealantmaterial. After installation, the downwardly most directed plug 99 canbe removed to allow for drainage of fluid and contaminants out of theslack adjuster 10 and away from the critical operating area 70 of theslack adjuster 10.

Reference is now made to FIG. 8, which shows a double-acting slackadjuster, generally indicated as 300, including a drainage system, inaccordance with another embodiment of the present disclosure. The slackadjuster includes a drainage system, generally indicated as 310,configured to allow fluid and/or contaminates to drain out of the mainspring housing 320 of the slack adjuster 300 to reduce exposure of thecritical operating area 70, as shown in detail in FIG. 1A, to fluidand/or contaminants

With continuing reference to FIG. 8, the slack adjuster 300 is similarto the slack adjuster discussed in detail above with regard to FIGS.1-3, where like reference numerals denote like components. The slackadjuster 300 includes the elongated hollow cylindrical housing member 12having a first end 15 and a second end 17. The second end 17 of thehousing member 12 includes the cap 100 and the wiper seal 102, asdiscussed in detail above. The first end 15 of the housing member 12also includes the control rod 19. The elongated cylindrical housingmember 12 includes the main spring housing portion 320, the cone nuthousing portion 22, and the over travel housing portion 24. The slackadjuster 300 also includes the rod assembly 25 including an elongatedrod member 26 positioned for reciprocal movement within the housingmember 12 through the second end 17 of the housing member 12. The rodmember 26 is restrained against rotation and pivotally connectable at afirst end thereof to the railway brake rigging by the rear jaw 18. Therod member has a threaded portion 30 adjacent a second end 32 thatextends into the housing member 12 and through the first end 15 of thehousing member 12.

In addition to the vented end cap 100, 200 and the drainage system 95,in the over travel housing portion 24, the slack adjuster can includeanother drainage system 310 which is associated with the main springhousing portion 320. The drainage system 310 allows fluid, such aswater, and other contaminants and/or debris, which pools/accumulates orfollows the path of least resistance into the main spring housing 320,to drain out of the slack adjuster 300 to prevent this fluid and/orcontaminants from contacting the critical operating area 70 of the slackadjuster 300.

The drainage system 310 includes a plug housing 325 which is fittedabout the main spring housing 320. The plug housing 325 can have threadslocated at opposing ends thereof. The main spring housing 320 can besplit into two separate members 320 a, 320 b which are associated withone another by the plug housing 325 so as to provide an opening or gap321 located therebetween. According to one embodiment, threads can beprovided on the facing end portions of separate members 320 a, 320 b ofthe main spring housing 320 which can be threadedly secured to thethreads of the plug housing 325. It can be appreciated that the drainagesystem 310 of the present disclosure can be used with new slack adjustersystems or can be retrofitted to existing slack adjuster systems bymodification of the main spring housing 320. According to anotherembodiment, the main spring housing 320 can be modified to be aone-piece member including one or more openings therein which can beused with or without the plug housing 325.

The plug housing 325 can include at least one aperture 330 extendingthrough a sidewall portion thereof. The aperture 330 is configured toform a direct egress for the fluid and/or contaminates to drain throughopening 321 of the main spring housing 320 and out of the main springhousing 320 and the slack adjuster 300 to reduce and/or to prevent thefluid and/or contaminants from entering into the critical operating area70 of the slack adjuster. Multiple apertures 330 can be located aboutand extending through the sidewall portion of the plug housing 325. Asstated above, the main spring housing 320 can be a one-piece member andthe drainage apertures 330 can extend through the sidewall of thehousing 320 itself with or without the housing.

A patch 335 or a plug, such as the plug 99, can be provided to cover orplug the apertures 330. If using a plug, this plug can be in the form ofa one-way valve or any other type of plug as discussed above, and eachof the apertures 330 can include the plug or one-way valve therein. Theuse of a one-way valve allows for drainage from the drainage area andprovides a means to prevent any contaminants from entering back throughthe drainage area. According to one embodiment, one or more of thepatches 335 or plugs can be removed, such as the patch 335 or plugfacing downward, after installation of the slack adjuster assembly inthe brake rigging. This would allow for quicker, unrestricted drainageof the water and/or contaminants from the drainage area of the slackadjuster 300. A single patch 335, or multiple patches 335 can beprovided which are configured for covering the apertures 330. Afterinstallation, the user would remove one or two of the patches 335 facingthe most downward position. This will allow the water and/orcontaminants to drain out of the slack adjuster 300. The remainingpatches 335 can be left covering the apertures 330 to protect theapertures 330 and prevent any water and/or contaminants from enteringinto the slack adjuster 300. It can also be appreciated that anycombination of plugs 99, one-way valves, and/or patches 335 can be usedto sealingly and/or removably engage the apertures 98, 330.

According to a further embodiment, one or more of the apertures 330 canbe filled with a sealant, such as an epoxy or any other known sealantmaterial, which can be removed or “popped out” of the aperture 330 toenable drainage therethrough. According to yet another embodiment, theplug can be in the form of a rounded, low-profile button shaped plug,such as shown in FIG. 8.

In addition to the drainage systems 95, 310 and the vented end caps 100,200, described in detail above, various interior sealing arrangementscan be provided to prevent fluid and/or contaminants from entering intoand accumulating in the critical operating area of the slack adjuster10, 300.

According to one embodiment, the conical spring seat 76 can be arubberized washer. The rubberized washer can include a rubber material,such as nitrile, Viton, EPDM, and the like, which is associated with theinner portion and outer portion of the washer. It can be appreciatedthat the rubber material can be associated with the washer by any knowntechnique, such as molded, vulcanized, glued, fastened, and the like.The rubberized inner portion and outer portion form sealing mechanismson the spring seat 76. Also, the rubberized portion on the washer innerportion acts as a splash guard, as well as preventing the accumulationof materials, water, contaminants, etc. from moving from the main springhousing 20, 320 into the cone nut housing 22 which contains the criticaloperating area 70 of the slack adjuster 10, 300. During assembly of themain spring housing 20 with the cone nut housing 22, the mating surfacesof the housings compress the rubber of the spring seat 76 into anyremaining open areas between the housings 20, 22, sealing the area fromany water intrusion from either the threads or from contaminants goingover or under outer diameter of the spring seat 76. The rubber materiallocated on the inner diameter of the spring seat 76 acts as a guardagainst splashing or rolling water from entering through the centralopening of the spring seat 76. The rubber material on the inner diametercan be configured according to several embodiments. According to oneembodiment, the material can simply make contact with the threaded rod.According to another embodiment, the rubber material can be threaded tointerlock with the rod. According to yet another embodiment, the rubbermaterial can be oversized to act as a mitigator of contaminants ratherthan a full sealing system.

Reference is now made to FIGS. 9 and 10, which show a double-actingslack adjuster, generally indicated as 400, including a drainage system,in accordance with another embodiment of the present disclosure. Theslack adjuster includes a drainage system, generally indicated as 410,configured to allow fluid and/or contaminates to drain out of the mainspring housing 420 of the slack adjuster 400 to reduce exposure of thecritical operating area 70, as shown in detail in FIG. 1A, to fluidand/or contaminants

With continuing reference to FIGS. 9 and 10, the slack adjuster 400 issimilar to the slack adjusters discussed in detail above with regard toFIGS. 1-3 and FIG. 8, where like reference numerals denote likecomponents. One difference between the slack adjuster 400 and the slackadjuster shown in FIG. 8, is the use of a single patch 435, shown indetail in FIG. 11, to cover apertures 430 in the main spring housing420. This slack adjuster 400 also differs from the slack adjuster shownin FIG. 8 in that apertures 430 are formed directly in the sidewall ofthe main spring housing 420 and the location of these apertures 430 arelocated toward the second end 17 of the main spring housing 420. It canbe appreciated that these drainage apertures 430 can be provided at anylocation along the main spring housing, including but not limited to thefirst end 15, second end 17, or a central portion, as shown in FIG. 8,of the main spring housing 320, 420. Also, it can be appreciated thatthe multiple patches 335 shown in FIG. 8 can be replaced with the singlepatch 435, shown in FIGS. 9 and 10. Additionally, the plugs 99, shown inFIG. 8, which are used for closing the apertures 98 in the plug housing97 that encompasses the over travel housing portion 24 can be replacedwith the single patch 435, as shown in FIGS. 9 and 10. As stated above,the present invention encompasses designs which do not include a plughousing 97, but wherein the apertures 98 are formed directly in the wallportion of the over travel housing portion 24.

The single patch 435 can be sized such that it encompasses approximately¾ of the circumference of the main spring housing 420 or the over travelhousing 24, the plug housing 325 encompassing the main spring housing320, shown in FIG. 8, or the plug housing 27 encompassing the overtravel housing 24. Thus, the single patch 435 covers all but at leastone aperture 430, 98. According to one embodiment, the single patch 435would cover three of the four apertures 430, 98. According to anotherembodiment, the single patch 435 would cover all but one or a fewapertures, so that upon installation, the uncovered area will be facingin a downward direction, allowing for drainage through these apertures.As shown in FIG. 11, the patch 435 can include labelling directing theinstaller as to which direction to secure the slack adjuster within thebraking system.

One material that can be used to form the patches 335, 435 can be 3M™FRA Railcar tape, which is common in the freight industry and istypically used for FRA regulations on railcars and locomotives. Forexample, the material used to form the patches can be 3M™ Scotchcal™Series 8000-10 and can include a poly over laminate. It can beappreciated that other materials and/or tapes can be used to form thepatches 335, 435 as long as the material has sufficient strength andholding characteristics capable of withstanding the environmental andmechanical conditions to which it will be exposed.

According to another embodiment, the sealing system can include asealing member configured for cooperating with at least one of the firstend 22 a and the second end 22 b of the cone nut housing portion 22.According to one design, the sealing member can comprise an O-ringand/or a sealing material associated with the first end 22 a of the conenut housing portion 22. It can be appreciated that the sealing memberscan be any known sealing members including gaskets, O-rings, rubbersealant material, adhesive sealing compound, and the like.

According to another design, the sealing member can cooperate with thethreads located at the first end 42 a of the rod guide 42 whichinterengage with the threads located at the first end 22 a of the conenut housing portion 22. According to one design, a thread lockingsealing material such as Loctite® can be positioned around the threadsof the rod guide 42. In this design, the sealing member forms aninteractive seal between the threads of the rod guide and the threads atthe first end 22 a of the cone nut housing portion 22 to prevent fluidand/or contaminants from entering the cone nut housing portion 22through the cooperating threads.

As discussed above, the first end 42 a of the rod guide 42 can includeat least one trigger pin 84 located within an aperture 86 in the firstend 42 a of the rod guide 42. The slack adjuster 10 can include aplurality of trigger pins 84, each of which are located within anaperture 86 in the first end 42 a of the rod guide. According to yetanother design, the sealing system can include at least one O-ring 92,or multiple O-rings, as needed, associated with a body portion of the atleast one trigger pin 84 to prevent fluid and/or contaminants fromentering the cone nut housing portion 22 through the aperture 86 in therod guide 42. It can be appreciated that the O-ring can be formed fromany well-known materials such as ethylene propylene diene monomer(EPDM), nitrile, fluoroelastomers such as Viton® or FKM(fluoroelastomers), silicone and the like.

It can be appreciated that any of the sealing systems described abovecan be used alone or cumulatively in any combination to achieve thenecessary sealing of the slack adjuster assembly 10 so as to protect thecritical operating area 70 from fluid and/or contaminants. It can alsobe appreciated that the slack adjuster 10, 300 can include sealingsystems using sealing members located at other locations along thehousing member 12 of the slack adjuster 10, 300, such as in cooperationwith the main housing portion 20, 320 and/or the over travel housingportion 24 as long as these sealing members prevent the entrance offluids and/or contaminants from entering into the critical operatingarea 70 of the slack adjuster 10. Furthermore, any of the sealingsystems or drainage systems described above can be used alone orcumulatively in any combination, with or without the vented end cap.

While the present disclosure is satisfied by embodiments in manydifferent forms, there is shown in the drawings, and described herein indetail, the preferred embodiments of the disclosure, with theunderstanding that the present disclosure is to be considered asexemplary of the principles of the disclosure and is not intended tolimit the disclosure to the embodiments illustrated. Various otherembodiments will be apparent to and readily made by those skilled in theart without departing from the scope and spirit of the disclosure. Thescope of the disclosure will be measured by the appended claims andtheir equivalents.

The Invention claimed is:
 1. An end cap for a main spring housing of aslack adjuster, the end cap including an inner portion having an innerseal surface configured for cooperating with an elongated rod member andan outer seal surface configured for cooperating with an inner surfaceof a sidewall located at an end portion of the main spring housing,wherein the end cap is radially interior to the main spring housing, andwherein the end cap includes at least one opening configured to allowfluid and/or contaminants to drain therethrough and out of both the endcap and the main spring housing.
 2. The end cap of claim 1, wherein theat least one opening comprises a radially extending aperture in fluidcommunication with the inner portion and the outer seal surface.
 3. Theend cap of claim 2, wherein the radially extending aperture ispositioned at a location to allow the fluid and/or contaminants to drainout of the inner portion of the end cap prior to breaching the innerseal.
 4. The end cap of claim 2, wherein the radially extending apertureis associated with an aperture extending through the sidewall located atthe end portion of the main spring housing.
 5. The end cap of claim 2,wherein the at least one opening includes a plurality of openings andwherein each of said openings includes a radially extending apertureassociated therewith.
 6. The end cap of claim 2, further comprising alongitudinally extending aperture in fluid communication with theradially extending aperture and an interior of the main spring housing,wherein the longitudinally extending apertures is capable of drainingfluid and/or contaminants out of the main spring housing.
 7. The end capof claim 1, wherein the at least one opening comprises a cut-out portionin the outer seal surface.
 8. The end cap of claim 1, wherein the atleast one opening further comprises a channel formed in the outer sealsurface, the channel being defined by a first lip portion and a secondlip portion.
 9. The end cap of claim 8, wherein the first lip portionhas a first height and the second lip portion has a second height andwherein the first height is less than the second height.
 10. The end capof claim 9, wherein the cap is associated with the main spring housingsuch that the first lip portion faces in an outward direction withrespect to the interior of the main spring housing and the second lipportion faces the interior of the main spring housing.
 11. The end capof claim 8, wherein the at least one opening further includes a cut-outportion in the outer seal surface, wherein the cut-out portion extendsthrough the first and second lip portion in a direction that isperpendicular with respect to the channel.
 12. The end cap of claim 11,wherein the at least one opening comprises a plurality of cut-outportions.
 13. The end cap of claim 8, wherein the inner portioncomprises an inner channel defined by a first ledge portion and a secondledge portion, wherein the first ledge portion defines a first diameterand the second ledge portion defines a second diameter, and wherein thefirst diameter is greater than the second diameter.
 14. The end cap ofclaim 13, wherein the channel defines a third diameter that is greaterthan the first and second diameters.
 15. The end cap of claim 8, whereinthe channel defined by the first lip portion and the second lip portionis integrally formed with the cap.
 16. The end cap of claim 8, whereinthe second lip portion includes an angled surface.
 17. A drainage systemfor use with a slack adjuster for a railway brake rigging, the slackadjuster including at least a main spring housing and a cone nut housingenclosing a critical operating area of the slack adjuster, wherein thecritical operating area includes components configured to operatetogether to adjust the brake rigging, the drainage system including anend cap having an inner portion having an inner seal surface configuredfor cooperating with an elongated rod member and an outer seal surfaceconfigured for cooperating with an inner surface of a sidewall locatedat an end portion of the main spring housing, the end cap being radiallyinterior to the main spring housing and the end cap including at leastone opening configured to allow fluid and/or contaminants to draintherethrough and out of both the main spring housing and the end cap toreduce exposure of components within the main spring housing andexposure of the critical operating area of the slack adjuster to thefluid and/or contaminants.
 18. The drainage system of claim 17, whereinthe at least one opening comprises a radially extending aperture influid communication with the inner portion and the outer seal surfaceand the system further includes an aperture extending through thesidewall located at the end portion of the main spring housing inalignment with the radially extending aperture through the end cap, andwherein the radially extending aperture is positioned at a location toallow the fluid and/or contaminants to drain out of the inner portion ofthe end cap and the housing sidewall prior to breaching the inner seal.19. The drainage system of claim 18, further comprising a longitudinallyextending aperture in fluid communication with the radially extendingaperture and an interior of the main spring housing, wherein thelongitudinally extending aperture is capable of draining fluid and/orcontaminants out of the main spring housing.
 20. The drainage system ofclaim 17, wherein the at least one opening further comprises a channelformed in the outer seal surface, said channel being defined by a firstlip portion having a first height and a second lip portion having asecond height, wherein the first height is less than the second height.21. The drainage system of claim 20, wherein the end cap is associatedwith the main spring housing such that the first lip portion faces in anoutward direction with respect to the interior of the main springhousing and the second lip portion faces the interior of the main springhousing.
 22. The drainage system of claim 18, wherein the at least oneopening further includes a cut-out portion in the outer seal surfacewherein the cut-out portion extends through the first and second lipportions in a direction that is perpendicular with respect to thechannel.
 23. The drainage system of claim 17, wherein the inner portioncomprises an inner channel defined by a first ledge portion having afirst diameter and a second ledge portion having a second diameter, andwherein the first diameter is greater than the second diameter.
 24. Thedrainage system of claim 23, wherein the channel defines a thirddiameter that is greater than the first and second diameters.
 25. Amethod of preventing the accumulation of fluid and/or contaminantswithin a slack adjuster and for protecting a critical operating area ofthe slack adjuster, the slack adjuster including a main spring housinghaving an end cap cooperating with an inner surface of a sidewall of themain spring housing and a cone nut housing enclosing the criticaloperating area of the slack adjuster, the method comprising positioningthe end cap radially interior to the main spring housing and providingat least one opening in the end cap, the at least one opening beingconfigured to allow fluid to drain out of both the end cap and mainspring housing to reduce exposure of components within the main springhousing and exposure of the critical operating area of the slackadjuster to the fluid and/or contaminants.
 26. The method of claim 25,wherein the end cap comprises an inner portion having an inner sealsurface configured for cooperating with an elongated rod member and anouter seal surface configured for cooperating with the inner surface ofthe sidewall located at an end portion of the main spring housing, andwherein the at least one opening comprises at least one of a radiallyextending aperture in fluid communication with the inner portion and theouter seal surface, at least one cut-out portion in the outer sealsurface, and a channel in the outer seal surface defined by a first lipportion and a second lip portion.
 27. A double acting tension actuatableslack adjuster to adjust the slack in a railway vehicle brake linkage,the slack adjuster comprising: (a) an elongated hollow cylindricalhousing member which is restrained against rotation and pivotallyconnectable at a first end thereof, the elongated hollow cylindricalhousing including a main spring housing having an end cap at an endthereof and located radially interior to the main spring housing, a conenut housing, and an over travel housing; (b) an elongated rod memberextending through the end cap, the rod member being restrained againstrotation and pivotally connectable at a first end thereof, the rodmember having at least a portion thereof threaded, the threaded portionof the rod member extending into the housing member through a second endof the housing member; (c) a cone lock nut threadedly engaged with thethreaded portion of the rod member intermediate a first and second endthereof, the cone lock nut axially movable for rotating about thethreaded portion of the rod member to change the length of the slackadjuster by changing the relative longitudinal position between thehousing member and the rod member, the cone lock nut being locatedwithin the cone nut housing; (d) at least a first spring for urging thecone lock nut into a first position with respect to the housing member;(e) a second spring for overcoming a force applied by the first springand for urging the cone lock nut into a second position; and (f) atleast one drainage system including at least one opening for allowingfluid and/or contaminants to drain out of the slack adjuster, the atleast one drainage system being associated with the end cap of the mainhousing, wherein the end cap includes an outer seal surface forcooperating with an inner surface of a sidewall located at an endportion of the main spring housing, and wherein the fluid and/orcontaminants drain out of both the main spring housing and the end cap.28. The slack adjuster of claim 27, wherein the end cap comprises aninner portion having an inner seal surface configured for cooperatingwith the elongated rod member and wherein the at least one openingcomprises at least one of a radially extending aperture in fluidcommunication with the inner portion and the outer seal surface, atleast one cut-out portion in the outer seal surface, and a channel inthe outer seal surface defined by a first lip portion and a second lipportion.
 29. The slack adjuster of claim 27, further including at leastone opening in the over travel housing portion, said at least oneopening configured to allow fluid and/or contaminants to drain throughthis at least one opening to reduce exposure of the critical operatingarea of the slack adjuster to the fluid and/or contaminants.
 30. Theslack adjuster of claim 27, further including at least one opening inthe main spring housing, said at least one opening configured to allowfluid and/or contaminates to drain through this at least one opening toreduce exposure of the critical operating area of the slack adjuster tothe fluid and/or contaminants.
 31. The slack adjuster of claim 29,including at least one of a plug, a one-way valve, and a patchconfigured for cooperation with the at least one opening in the overtravel housing portion.
 32. The slack adjuster of claim 30, including atleast one of a plug, a one-way valve, and a patch configured forcooperation with the at least one opening in the main spring housing.33. The slack adjuster of claim 27, including a sealing systemconfigured for cooperating with at least one of the main housingportion, cone nut housing portion, and over travel housing portion toseal the critical operating area against entrance of fluid and/orcontaminants therein or to reduce exposure of the critical operatingarea to fluid and/or contaminants.